Method and apparatus for conditioning sheet metal

ABSTRACT

A metal processing apparatus, comprising a pay-off reel for supporting and uncoiling a coil of metal, a roller-leveler apparatus adapted to receive a strip of sheet metal from the pay-off reel for conditioning the strip of steel, a recoiler for re-coiling the coil of metal, and whereby the apparatus generates enough tension on the strip of metal to improve flatness and remove coil breaks from the strip of metal as it advances through the roller-leveler.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. Provisional Patent Application No. 60/713,174 filed Aug. 31, 2005 from which priority is claimed, and is hereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable.

BACKGROUND OF THE INVENTION

The present invention relates to flat rolled metal and sheet metal processing. More particularly, the present invention relates to a method and apparatus for removing coil breaks and leveling metal using a roller-leveling machine in combination with high tension on the metal to enhance conditioning of the metal with a conditioning apparatus.

A wide range of goods contain components manufactured from processed sheet metal, such as aircraft, automobiles, file cabinets and household appliances, to name only a few. Typically, the sheet metal is purchased directly from steel mills or steel service centers. However, some applications require that the sheet metal first pass through intermediate processors (sometimes referred to as “toll” processors) to refine the sheet metal before an original equipment manufacturer receives it. In many applications, the flatness and surface condition of the sheet metal is important. Flatness of sheet metal is important for virtually all stamping and blanking operations, while good surface conditions are important in applications where the surfaces of the metal sheet will be painted.

Sheet metal straight from the mill typically contains a layer of “scale” on its surfaces. Scale is a layer of iron oxide that forms on the surface of hot rolled carbon steel while the steel is cooled. The rate at which the product is cooled, and the total temperature drop affects the amount and composition of scale that forms on the surface. Iron has a complex oxide structure with FeO (“wustite”) mechanically bonded to the base metal substrate, followed by a layer of Fe₃O₄ (“magnetite”) chemically bonded to the wustite, and then a layer of Fe₂O₃ (“hematite”) chemically bonded to the magnetite and exposed to the air. Typically, scale is removed in a pickling process in which the steel sheet is run through a sulfuric acid bath. Then a coating of oil is applied to prevent the sheet from rusting.

A number of common defects affect sheet metal flatness, including “coil set”, “edge wave”, “center buckle”, and “coil break”. “Coil set” occurs when sheet metal is rolled into coil form for convenient storage and transportation and the strip takes on a coiled shape, which commonly referred to as “coil set.” Coil set occurs because the sheet metal has been bent past its yield point. More specifically, when sheet metal is coiled, the metal near the inside surface of the curved sheet is compressed past its yield point, and the metal near the outside surface of the curved sheet is stretched past its yield point. “Edge wave” occurs if the edge portions of the sheet are longer than the center portion of the sheet, resulting in undulations along one or both of the edge portions of the sheet. “Center buckle” results if the center portion of the sheet is longer than one or both of the edge portions, which results in bulging or undulating of the central portion of the sheet. “Coil break” occurs when defects in the sheet metal cause it to kink as it uncoils from the “pay-off” reel. This results in creases or ridges appearing in sheets as parallel lines transverse to the direction of rolling and generally extending across the width of the sheet.

Various methods exist for leveling sheet metal. For example, a conventional flattening device such as a stretcher-leveler or tension-leveler can correct coil-set, edge wave, and center buckle. A stretcher-leveler grips the sheet metal strip in segments and stretches each segment individually. As such it operates relatively slowly. A tension leveler uses trailing and leading bridle rollers over which the metal strip passes in a serpentine configuration. The leading rollers rotate slightly faster than the trailing rollers, and hence the sheet stretches between them. However, stretcher-levelers and tension-levelers can be cost-prohibitive. In addition, the only apparatus known to the inventors that is believed to remove coil breaks from sheet metal is a temper-mill. The large size and high cost of temper-mills make them cost-prohibitive and difficult to combine with other processing equipment.

Once the sheet metal is leveled, it lends itself to a conditioning procedure to remove the scale without the need for pickling and oil coating. Basically, the procedure involves subjecting the leveled sheet metal to brushes that remove most of the scale, indeed, all but the wustite. With the sheet so conditioned, it readily accepts paint, yet does not require oil to prevent further oxidation. See U.S. Pat. Nos. 6,732,561; 6,814,815; and 6,205,830, hereby incorporated by reference.

One can achieve a measure of flatness in a sheet metal strip at modest expense by passing the metal strip through a roller-leveler having a succession of rollers that cause the strip to undergo multiple undulations. While a conventional roller-leveler is a less costly flattening apparatus, it has been considered ineffective. Depending on the severity of the defects, the roller-leveler produces a reasonably flat metal sheet. However, sheet metal with moderate to severe defects cannot be sufficiently flattened. In addition, there still exists a neutral axis in the sheet metal where the yield point of the metal has not been exceeded by the small diameter rollers. Metal lying at or near this neutral axis may be in a stressed condition (and tend to spring back toward its original shape) because it has not been deformed past its elastic limit. Therefore, even after roller leveling, the material at or near the neutral axis will possess internal residual stresses, because the grain structure is not uniform. The roller-leveler does not consistently leave the sheet metal flat enough for conditioning with brushes.

Thus, there is a need for a cost-effective sheet metal processing apparatus that removes coil breaks in a continuous strip of sheet metal, improves flatness, and conditions the sheet metal by removing scale.

SUMMARY OF THE INVENTION

Briefly stated, the invention is a metal processing apparatus comprising a pay-off reel for supporting and uncoiling a coil of metal and a take-up reel for re-coiling the coil of metal and placing tension on a strip of metal between the pay-off reel and take-up reel. A roller-leveler apparatus is adapted to receive the strip of sheet metal from the pay-off reel, improves flatness, and remove coil breaks from the metal. A surface conditioning apparatus has at least one brush adapted for engagement with a surface of the strip of metal in a manner to remove scale from the surface.

The foregoing and other features, and advantages of the invention as well as embodiments thereof will become more apparent from the reading of the following description in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form part of the specification:

FIG. 1 is a elevation view of a sheet metal processing apparatus in accordance with and embodying the present invention;

FIG. 2 is a side view of a leveler;

FIG. 3A is a side view of a first embodiment of a surface conditioner;

FIG. 3B is a exploded perspective view of a translating mechanism;

FIG. 3C is a side view of a second embodiment of the surface conditioner;

FIG. 4 is a side view of a cleaning module;

FIG. 5 is a plan view of the cleaning module;

FIG. 6 is a side view of a modified cleaning module;

FIG. 7 is a side view of a take-up reel;

FIG. 8 is a enlarged perspective view of a mandrel of the take-up reel;

FIG. 9 is an exploded view of the mandrel of the take-up reel of FIG. 8; and

FIG. 10 is a section view of the mandrel along section line 10-10 of FIG. 8.

Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.

DETAILED DESCRIPTION

The following detailed description illustrates the invention by way of example and not by way of limitation. The description clearly enables one skilled in the art to make and use the invention, describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention. Additionally, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Referring now to the drawings, a sheet metal processing apparatus A conditions sheet metal that is supplied in a roll B, typically from a hot strip mill. As such, the sheet metal contains a scale on both of its surfaces, generally oxides of iron that take the form of wusite (FeO) bonded directly to the surface of the steel, magnetic (Fe₃O₄) bonded to the wusite, and hematite (Fe₂O₃) bonded to the magnetite. The scale renders the steel unsuitable for most products manufactured from sheet steel and is thus removed—indeed, in the processing apparatus A. Actually, as explained in U.S. Pat. No. 6,814,815, which is incorporated herein by reference, only the hematite and magnate need be removed to provide steel sheet suitable for conversion into panels and the like that are painted or otherwise used in manufactured items. It is believed that the wusite serves to protect the steel sheet from oxidation at its surfaces and thus should be retained. As such, it serves as a substitute for an oil which film is applied after the more traditional picketing which the apparatus A eliminates.

Apart from the scale, the steel on the roll B may have defects that affect sheet metal flatness, such as edge waves, coil set, or center buckles, which exist in the roll B itself. But for processing in the apparatus A, the coiled steel sheet must be withdrawn from the roll B in the form of a strip S. As the strip S is withdrawn, it may acquire coil breaks.

The preferred embodiment of apparatus A includes (FIG. 1) a payoff reel 2 that holds the roll B, a crop shear 4 for cutting off the leading end of the strip S, a roller leveler 6 for flattening the strip S, a side trimmer 8 for trimming the sides of the strip S, a surface conditioner 10 where the actual scale is removed, at least down to the wusite, and finally a recoiler 12. The foregoing components act upon the strip S in the order identified.

The payoff reel 2 (FIG. 1) can be any payoff reel known to those skilled in the art and, as such, the preferred embodiment includes a mandrel 18 that actually supports the roll B of sheet metal. As the sheet metal strip S pays off the roll B, the mandrel 18 rotates, but under the control of a brake 20 to impart a measure of tension to the strip S. Moreover, the reel 2 has a peeler 22 to deflect the strip S away from the roll B notwithstanding the coil set imparted to the sheet metal in the roll B.

The crop shear 4 (FIG. 1) likewise can be any crop shear known to those skilled in the art. In the preferred embodiment, it slices a short segment from the strip S at the leading edge of the strip S so as to eliminate imperfections from the leading edge and render the leading edge perpendicular to the side edges. This facilitates threading through the surface conditioner 10 and enables the recoiler 12 to firmly grip the end of the strip S to thereby apply a substantial tensile force to the strip S.

The leveler 6 also can be any leveler known to those skilled in the art. In the preferred embodiment, it has (FIG. 2) a frame 24 that supports upper and lower working rollers 26 and 28, respectively, and backing rollers 30 behind the working rollers 26 and 28 to prevent the rollers 26 and 28 from deflecting. The rollers 26 and 28 extend transversely with respect to the strip S, each for at least the full width of the strip S. Moreover, the upper rollers 26 are offset horizontally with respect to the lower rollers 28 in the direction of advance for the strip S and are further offset vertically so that the lower surface areas of the upper rollers 26 extend below the upper surface areas 28 of the lower rollers 28. The lower rollers 28 are supported on a carrier 32 that is in turn supported on the frame 24. The carrier can be raised and lowered and inclined slightly to control the vertical offset between the upper and lower rollers 26 and 28 through the leveler 6. Moreover, the amount of vertical offset is adjustable across the width of the rollers 26 and 28. The backing rollers 30 lie behind the upper and lower working rollers 26 and 28 and retard deflection of the working rollers 26 and 28. One such type of leveler is sold by Butech, Inc., located in Salem, Ohio, and Red Bud Industries, located in Red Bud, Ill.

Initially, to thread the strip S through the leveler 6, the rollers 26 and 28 are powered by an electric motor 36 which transmits its power to the rollers 26 and 28 through a gear box (not shown). Once the strip S is secured to the recoiler 12, the strip S is pulled through the leveler 6 by the recoiler 12. During operation, the linear velocity of the strip S is controlled by the recoiler 12. The strip S passes between the upper and lower working rollers 26 and 28, which assume an undulated configuration. Indeed, the undulations are such that they cause elastic and plastic deformation in the strip S. This serves to remove some of the coil set from the strip S and some of the edge wave and center buckle as well, assuming that there is some. In combination with the substantial tension applied to the strip S by the recoiler 12, it also removes coil breaks.

The surface conditioner 10 performs much more effectively when substantial tension is applied to the strip S by the recoiler 12. As the recoiler 12 pulls the strip S, tension is developed through resistance primarily at the leveler 6, but also at the payoff reel 2. The additional tension causes additional elastic and plastic deformation, which enhances the temporary and permanent flatness in the strip S. As a result, the tension further levels the strip S for more effective removal of the scale by the surface conditioner 10. Enough working rollers 26 and 28 exist with sufficient vertical offset to prevent the tension applied to the strip S from simply pulling the strip S through the leveler 6 with the strip S sliding over the surfaces of the rollers 26 and 28. Very little, if any, slippage occurs between strip S and the upper and lower working rollers 26 and 28.

The side trimmer 8 (FIG. 2) cuts off a small segment along the side of the strip S, thus eliminating imperfections in the side edges and leaving the strip S with clean side edges that are straight, parallel and cut to a specific width. The trimmer 8 likewise can be any trimmer known to those skilled in the art.

The surface conditioner 10 removes at least some of the scale from both surfaces of the strip S while the strip S is maintained under substantial tension applied at the recoiler 12 and resisted primarily at the leveler 6, but also at the payoff reel 2. Preferably, the surface conditioner 10 removes the layers of hematite and magnetite, while leaving the layer of wusite bonded to the steel.

The surface conditioner 10 includes (FIG. 3) a fixed frame 38 and a subframe 40 that is supported within the fixed frame 38 on a pair of tracks 44, so that it can translate to and fro in a direction transverse to the direction of advance of the strip S. To this end, the subframe 40 has wheels 46 that roll over the tracks 44. The subframe 40 is coupled with a translating mechanism 48, which moves in an oscillating motion back and forth over the track 44 with the midpoint of the movement coinciding with the centerline of the strip S. This oscillating motion promotes more uniform wear of several cleaning modules 60 (FIG. 3), which are attached to the subframe 40 and described below in more detail. The range of movement is relative to the width of the strip S and should be great enough to allow the entire surface of the cleaning module 60 to be utilized. Its frequency should range between 1 and 3 cycles/min. and preferably 2 cycles/min.

In the embodiment depicted in FIGS. 3A and 3B, the translating mechanism 48 is a hydraulic cylinder 49 mounted between the track 44 and the wheel 46. Position sensors (not shown) mounted on either side of the fixed frame 38 sense the relative position of the subframe 40 and accordingly send signals to the hydraulic cylinder 49 to extend and retract to oscillate the subframe 40 back and forth.

In an alternate embodiment depicted in FIG. 3C, the translating mechanism 48 includes a motor that drives a pair of sprocket. An endless loop chain engages with the pair of sprockets mounted to the subframe 40. Position sensors mounted on either side of the fixed frame 38 sense the relative position of the subframe 40 and accordingly send signals to the motor to oscillate the subframe 40 back and forth. Those skilled in the art will recognize that other embodiments of the translating mechanism can be used, such as motorized wheels attached to the subframe 40.

At the entrance to the surface conditioner 10, the fixed frame 38 supports drag pads 50 through which the strip S passes (FIGS. 1 and 3A). The pads 50 extend the full width of the strip S and can bear against both surfaces of the strip S with a force exerted by hydraulic motors 52 through leadscrews and an air bladder located behind the upper pad 50. Normally during operation, the drag pads 50 do not bear against the strip S. However, once the trailing end of the strip S leaves the payoff reel 2 the bladders exert force on the pads 50 to bear against the strip S to create the tension on the strip S in place of the payoff reel 2. At its discharge end, the fixed frame 38 supports pinch rollers 54 between which the strip S passes such that the rollers 54 bear against both surfaces of the strip S and maintain the strip S at a fixed elevation within the subframe 40 (FIG. 3A). Likewise at the entrance end the fixed frame 38 supports side rollers 56 that bear against the side edges of the strip S and prevent the strip S from displacing laterally.

Drag pads 51 are also located directly before the recoiler 12 (FIG. 1). These drag pads 51 bear against the strip S continuously during operation to insure that the strip S is tightly wound around the recoiler 12.

As mentioned above, the subframe 40 carries several cleaning modules 60 (FIG. 3) which actually remove the scale from the strip S. Each cleaning module 60 contains (FIG. 4) an upper brush 62 and a lower brush 64 which rotate against the upper and lower surfaces of the strip S directly opposite from each other, so that the tendency of the upper brush 62 to deflect the strip S vertically is offset by the lower brush 64 and visa versa. Preferably, the direction of rotation causes the surfaces of the brushes 62 and 64 at the area of contact with the strip S to move in the direction opposite the direction in which the strip advances. To this end, the brushes 62 and 64 are powered by an electric motor 66, with the velocity of each brush 62 and 64 at the area of contact being between 3000 and 4000 ft/min and preferably about 3500 ft./min. Each brush 62 and 64 is longer than the strip S is wide—indeed, long enough for it to remain in contact with the strip S for the full width of the strip S as the subframe 40 moves back and forth on the tracks 44. The translation back and forth across the strip S promotes more uniform wear in the brushes 62 and 64 and does not enable reoccurring imperfections in a particular region of the strip S from deforming the brushes 62 and 64. This in turn decreases the frequency at which the brushes 62 and 64 need to be dressed, so that the brushes last longer. In some instances, the need to redress brushes 62 and 64 can be eliminated altogether.

Each brush 62 and 64 possesses a generally cylindrical configuration about 14 in. in diameter. It includes (FIG. 4) a core 68, which is rotated by the motor 66, and bristles 70 that radiate from the core 66. The bristles 70 are nylon filaments impregnated with silicon-carbide, which possess a measure of flexibility. The flexibility of the bristles gives the brush the advantage of being compressible so that the brush compresses against the strip S during operation. This allows the bristles to remain in contact with the strip S even with variations in flatness, thereby, improving the performance of the surface conditioner 10. Suitable brushes may be obtained fromDanline, Inc. located in Springfield, N.J., or Hotani Co., Ltd., located in Wakayama, Japan.

A modified cleaning module 74 (FIG. 6) has upper and lower abrasive rolls 76 and 78 that are offset with respect to each other along the strip S. The upper roll 76 bears against the upper surface of the strip S and the lower roll 78 against the lower surface. To prevent the offset rolls 76 and 78 from deflecting the strip S, a backing roller 80 bears against the strip S opposite each of them. The rolls 76 and 78 are powered and revolve such that their surfaces move against the direction of advance for the strip S. The backing rollers 80 merely rotate with the advance of the strip S owing to their contact with the strip S.

Each roll 76 and 78 has a core 81 and a multitude of disks 82 set end to end along the core 76. The disks 82 contain abrasive particles, such as aluminum oxide. Disk-like rolls sold by Minnesota Mining and Manufacturing (3M) under the trademark Scotch Brite will suffice for the rolls 76 and 78. U.S. Pat. No. 6,814,815 describes the rolls 76 and 78 in greater detail.

In lieu of offsetting the upper and lower rolls 76 and 78 of each module 74, they may be positioned directly opposite each other, and this eliminates the need for the backing rollers 80.

Each cleaning module 60 or 74 carries a spray head 83 (FIGS. 4-6), which directs water spread into a spray at the area of contact between the brushes 62 and 64 and the strip S. The water serves as a lubricant to reduce friction between the brushes 62 and 64 or 76 and 78 and the strip S, which promotes cooler running operation. In addition, the water serves to flush from the brushes 62 and 64 the scale that is removed from the strip S. The modified cleaning modules 74 are likewise equipped with spray heads 83.

Beyond the last cleaning module 74 and its spray heads 83 the fixed frame 38 of the surface conditioner 10 supports several air knives 84 (FIG. 1) that direct high velocity air streams at both surfaces of the strip S to remove water from the strip S. Thus, the strip S advances to the recoiler 12 free of water, yet it is not coated with oil. Instead the wusite that remains on the cleaned surfaces of the strip S prevents oxidation at those surfaces.

The recoiler 12 draws the strip S through the surface conditioner 10 and winds it into a coil C (FIG. 7) all while maintaining tension on the order of 50,000 to 60,000 lbs. in the strip S for larger diameter coils and up to about 200,000 lbs. for smaller diameter coils. The tension of this magnitude further levels the strip S, making its surfaces flat enough for the brushes 62 and 64 or the rolls 76 and 78 to effectively remove both hematite and magnetic from the strip S. The leveler 6 offers the primary resistance to the force exerted by the recoiler 12, although the drag pads 50 and 51 and the brake 20 of the payoff reel 2 offer some resistance as well.

The recoiler 12 includes (FIG. 7) a base 86, a pair of pedestals 88 that are attached to the base 86, a mandrel 90 that at one end rotates in the pedestals 88, an electric motor 92 coupled to that end of the mandrel 90 through a gear reduction for rotating the mandrel 90, and a retaining arm 94 that extends between the opposite end of the mandrel 90 and the base 84. The rotating mandrel 90 winds the strip S about it into the coil C after the surface conditioner 10 has removed scale from the surfaces of the strip S. Moreover, the rotation of the mandrel 90 serves to maintain tension in the strip S and, thus, is subjected to substantial forces, which are transferred through the pedestals 88 and the retaining arm 94 to the base 86 which resists them. However, the retaining arm 94 is detachable from the end of the mandrel 90 to enable a fully wound coil C to be removed from the mandrel 90.

The mandrel 90 includes (FIGS. 8-10) a tubular arbor 96, one end of which is received in the pedestals 88 where it rotates in an antifriction bearing 98. Beyond the pedestals 88, the end of the arbor 96 is coupled with the electric motor 92, so that when the motor 92 is energized, it will exert torque on and rotate the arbor 96—indeed, the entire mandrel 90. At its opposite end, the arbor 96 is fitted with a hub 100 provided with a journal that is received in a bearing carried by the retaining arm 94. The hub 100 may be removed from the arbor 96 to expose the hollow interior of the arbor 96.

Within its hollow interior the arbor 96 contains an actuator assembly 102 having a pair of side plates 104 and hydraulic cylinders 106 located between the plates 104 and secured firmly to them. While the assembly 102 can float, so to speak, in the interior of the arbor 96, it cannot rotate with respect to the arbor 96. In other words, it has the capacity to shift a short distance along a single diameter in the arbor 96.

The strip S winds around the portion of the mandrel 90 that is located between the pedestal 88 and the retaining arm 94, and in this segment the arbor 96 has an axially directed rib 110 over which a wedge bar 112 fits. The bar 112 has beveled faces 114 along its sides, thus imparting a wedge-shaped configuration to its exterior. The bar 112 also has rods 116 that project through the rib 110 and into the hollow interior of the arbor 96 where they align with the cylinders 106 of the actuator assembly 102. Thus, when the cylinders 106 are energized, they urge the wedge bar 112 away from the arbor 96.

Directly opposite from the rib 110, that is to say 180° from it, the arbor 96 has a land 120 against which a clamping block 122 is firmly secured. The clamping block 122 contains a channel 124 (FIG. 10) that opens away from the arbor 96, with one of the sides of the channel 124 being undercut to provide a recessed clamping surface 126 that is presented toward the arbor 96. The channel 124 holds a clamping bar 130 having a clamping surface 132 that is presented opposite the clamping surface 126 on the block 122. The clamping bar 130 has rods 134 that pass into the arbor 96 at the land 120 and terminate within the hollow interior of the arbor 96 where they also align with the cylinders 106 of the actuator assembly 102. When the cylinders 106 are energized, they not only urge the wedge bar 112 away from the arbor 96, but they also urge the clamping bar 130 toward the clamping surface 126 on the clamping block 122.

Attached firmly against the exterior surface of the arbor 96 along each side of the clamping block 122 are several pivot mounts 138 (FIGS. 9 & 10). They serve as mounts for fixed shoes 140 having arcuate exterior surfaces that lie flush with the exterior surface of the block 122. The pivot mounts 138 also function as hinges for attaching expandable shoes 142 to the arbor 96. The expandable shoes 142 have arcuate exterior surfaces that lie generally flush with the arcuate surfaces of the fixed shoes 140 at the pivot mount 138. The arcuate span of the expandable shoes 142 exceeds the arcuate span of the fixed shoes 140, and indeed is great enough to enable those edges of the shoes 142 that are remote from the mounts 138 to lie along the beveled faces 114 of the wedge bar 112. Thus when the cylinders 106 are energized, the beveled faces 114 of the wedge bar 112 function as cams, so that the wedge bar 122 drives the expandable shoes 142 away from the arbor 96. The end of the two expandable shoes 142 are connected with links 146 to restrict the distance that they can spread away from each other.

The mandrel 90 receives the squared off edge of the strip S with the cylinders 106 of its actuating assembly 102 retracted. Indeed, the squared off edge is inserted into the channel 124 of the clamping block 122, so that it lies between the clamping surface 126 of the block 122 and the clamping surface 132 on the clamping bar 130. Thereupon, the cylinders 106 of the actuator assembly 102 are energized. They drive the clamping bar 130 farther into the channel 124, causing the end of the strip S to become clamped between the clamping surfaces 126 and 132 on the block 122 and bar 130, respectively. The cylinders 106 also drive the wedge bar 112 away from the arbor 96 and force the expandable shoes 142 away from the arbor 96, thereby increasing the size of the mandrel 90. The use of multiple cylinders 106 along the actuator assembly 102 provide a uniformly distributed force to the clamping bar 130 and the wedge bar 112, which enhances the ability of the recoiler to handle the high tensions it places on the strip S and allows the clamping bar 130 to compensate for thickness variations in the strip S. At this juncture, the electric motor 92 may be energized to wind the strip S around the expanded mandrel 90 and thus draw it through the surface conditioner 10.

In operation of the apparatus A, the coiled sheet is withdrawn from the pay-off reel 10 in the form of the strip S and “threaded” into the crop shear 4, which cuts off the leading edge. The strip S is threaded through the roller-leveler 6, side-trimmer 8, the surface conditioner 10, and into the recoiler 12.

Changes can be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 

1. A metal processing apparatus, comprising: a pay-off reel for supporting a metal roll; a roller-leveler adapted to receive a strip of sheet metal from the pay-off reel and to remove defects from the strip of sheet metal; and a recoiler adapted to receive the strip of sheet metal and recoil the strip of sheet metal; and wherein the apparatus generates enough tension on the strip of sheet metal to improve the flatness of the strip of sheet metal as it advances through the roller-leveler.
 2. The metal processing apparatus of claim 1, wherein the apparatus generates enough tension on the strip of sheet metal to remove coil breaks from the strip of sheet metal as it advances through the roller-leveler.
 3. The metal processing apparatus of claim 1, wherein tension is generated on the strip of metal by pulling the strip of metal with the recoiler against the resistance of the roller-leveler and the pay-off reel.
 4. The metal processing apparatus of claim 1, wherein the tension on the strip of metal is at least about 50,000 lbs.
 5. The metal processing apparatus of claim 1, wherein the tension on the strip of metal is between about 50,000 lbs. to about 200,000 lbs.
 6. The metal processing apparatus of claim 3, further comprising: at least one drag pad engaged with the strip of metal to provide resistance against the pull of the recoiler.
 7. The metal processing apparatus of claim 1, further comprising: a surface conditioning apparatus having at least one cleaning module adapted for engagement with a surface of the strip of metal in a manner to remove scale from the surface.
 8. The metal processing apparatus of claim 7, the surface conditioning apparatus comprising: a fixed frame; a subframe supported within the fixed frame on a pair of tracks; an translating mechanism coupled with the subframe to oscillate the subframe over a predetermined interval.
 9. The metal processing apparatus of claim 7, the cleaning module comprising: at least one brush that engages the surface of the strip of sheet metal in a manner to remove scale from the surface.
 10. The metal processing apparatus of claim 1, the recoiler comprising: a base; at least one pedestal attached to the base; a mandrel that at one end rotates in at least one pedestal to recoil the strip of sheet metal about the mandrel and maintain tension on the strip; a motor for rotating the mandrel.
 11. A metal processing apparatus for conditioning sheet metal, comprising: a pay-off reel for supporting a metal coil; a roller-leveler adapted to receive a strip of sheet metal; a recoiler for re-coiling the strip of metal and generating enough tension to improve flatness of the strip of metal as it advances through the roller-leveler.
 12. The metal processing apparatus of claim 11, wherein the recoiler generates enough tension to remove coil breaks from the strip of metal as it advances through the roller-leveler.
 13. The metal processing apparatus of claim 11, wherein tension is generated on the strip of metal by pulling the strip of metal with the recoiler against the resistance of the roller-leveler and the pay-off reel.
 14. The metal processing apparatus of claim 11, wherein the tension on the strip of metal is at least about 50,000 lbs.
 15. The metal processing apparatus of claim 11, wherein the tension on the strip of metal is between about 50,000 lbs. to about 200,000 lbs.
 16. The metal processing apparatus of claim 11, further comprising: at least one drag pad engaged with the strip of metal to provide against the pull of the recoiler, thereby generating tension on the strip of metal.
 17. The metal processing apparatus of claim 11, further comprising: a surface conditioning apparatus having at least one cleaning module adapted for engagement with a surface of the strip of metal in a manner to remove scale from the surface.
 18. The metal processing apparatus of claim 17, the surface conditioning apparatus comprising: a fixed frame; a subframe supported within the fixed frame on a pair of tracks; an translating mechanism coupled with the subframe to oscillate the subframe over a predetermined interval.
 19. The metal processing apparatus of claim 11, the recoiler comprising: a base; at least one pedestal attached to the base; a mandrel that at one end rotates in at least one pedestal to recoil the strip of sheet metal about the mandrel and maintain tension on the strip; a motor for rotating the mandrel.
 20. A method of improving flatness of a coil of metal, comprising: providing a pay-off reel for supporting the coil of metal; providing a roller-leveler for removing defects from the coil of metal; providing a recoiler; uncoiling a strip of metal from the pay-off reel; advancing the strip of metal through the roller-leveler; re-coiling the strip of metal with the take-up reel; and generating enough tension on the strip of metal to improve flatness of the strip of metal as it advances through the roller-leveler.
 21. The method of claim 20, further comprising, generating enough tension on the strip of metal to removes coil breaks from the strip of metal as it advances through the roller-leveler.
 22. The method of claim 20, further comprising: pulling the strip of metal with the take-up reel against the resistance of the roller-leveler and the pay-off reel to generate the tension on the strip of metal.
 23. A metal processing apparatus for improving flatness of a coil of metal, comprising: a means for uncoiling a coil of metal; a roller-leveler adapted to receive a strip of metal from means for uncoiling a coil of metal; a means for re-coiling the strip of metal and generating enough tension to improve flatness of the strip of metal as it advances through the roller-leveler.
 24. The metal processing apparatus of claim 23, further comprising a means for generating enough tension to remove coil breaks from the strip of metal as it advances through the roller-leveler.
 25. The metal processing apparatus of claim 23, the means for recoiling comprising: a tube; a clamp assembly attached to the tube; at least one shoe assembly pivotally attached to the tube; a plurality of cylinders attached to the tube and operatively connected to at least one shoe assembly for pivoting the shoe assembly between a contracted position and an expanded position and operatively connected to the clamp assembly for securing a leading edge of the strip of metal.
 26. The metal processing apparatus of claim 23, wherein the tension on the strip of metal is between about 50,000 lbs. to about 200,000 lbs. 